Effects of fermion flavor on exciton condensation in double-layer systems

We use a fermionic path-integral quantum Monte Carlo framework to study the effects of fermion flavor on the physical properties of dipolar exciton condensates in double-layer systems. We find that by including spin in the system the effective interlayer interaction strength is weakened, yet this has very little effect on the Kosterlitz-Thouless transition temperature. We further find that, to obtain the correct description of screening, it is necessary to account for correlation in both the interlayer and intralayer interactions. We show that while the excitonic binding cannot completely suppress screening by additional fermion flavors, their screening effectiveness is reduced by intralayer correlations leading to much higher transition temperatures than predicted with large-N analysis.